Elemental sulphur is an essential ingredient in a number of industrial applications including in crop fertilizer applications, ammunition manufacture, and rubber vulcanization, to name a few.
One of the problems in the prior art with the use of particulate sulphur in fertilizer applications is that when applied in the form of large particles greater than 100 micron size, elemental sulphur is very slow in reaching the needy roots of plants to pass on the required nutrients. This is because sulphur, in its original elemental form, is insoluble in water and hence cannot be absorbed by the roots of plants. However, bacteria in the soil feed on elemental sulphur and convert it to water soluble sulphate which is subsequently readily absorbed by plant roots.
The problem with direct application of water soluble sulphate fertilizers is that the method suffers from over dissolution, uncontrolled release and leaching during incessant precipitation leading to poor returns on farm input investment. However, with smaller sized particulate sulphur, at a particle size less than about 30 (<30) microns, absorption and conversion of particulate sulphur is optimal and much more effective. When applied to plants, finely divided micronized sulphur can provide the plants with nutrients in the same season of application—as such micronized sulphur (<30 microns) has tremendous value and application in the fertilizer industry. On this basis, if there were a practical or effective means of producing large quantities of micronized sulphur particles this would be of great use in the fertilizer industry.
There is also application for the use of micronized sulphur in ammunition manufacturing, since finely divided sulphur particles would combust with greater efficiency and effectiveness. Use of a consistent finely sized micronized sulphur particle in ammunition manufacture would, it is believed, result in the manufacture of a higher quality and more consistent ammunition.
The automobile and aviation tire manufacturing industry also use large quantities of fine sulphur powder for vulcanization of rubber. The reaction between sulphur and rubber results in very hard and durable rubber that can be maintained over a comparatively wide range of temperature. Thus, the finer the sulphur powder the better would be the reaction with rubber and the higher would be the quality of tire produced. In other applications, the paint industry also uses very fine sulphur powder as a color blend. Micronized sulphur is widely used as a fungicide, insecticide and pesticide, and also has medicinal uses for treating skin ailments in humans.
Current processes for the production of micronized sulphur powder are dangerous and energy inefficient. Micronized sulphur powder is quite often presently produced by pulverizing sulphur lumps in mechanical milling equipment. Particularly in circumstances where very finely sized particles are acquired, conventional milling results are dependent upon substantial energy consumption. As such, if it was possible to determine a method of production of micronized sulphur powder which either used means other than mechanical milling or a mechanical milling process that significantly decreased the energy requirement, it would be desirable from an economic perspective.
Another problem with current day milling technologies used to produce micronized sulphur powder is the fire and explosion risk and hazard presented by the milling process. Sulphur is a flammable and explosive substance, and by its nature mechanical milling can result in risk exposure to explosion. As such, people who are milling sulphur into a micronized product have in the past needed to install expensive fire prevention systems to protect personnel and prevent accidents. If it were possible to find a method of micronized and sulphur that lesson the risk of fire or explosion this would also be desirable over methods in the prior art.
Other shortcomings of the grinding process include the fact that the work environment is very loud for the operating personnel. In terms of the grinding media and the equipment as a whole, conventional grinding or milling technology requires ongoing maintenance and regular media replacement, which lead to increased production costs. Reduction of maintenance and media costs would be desirable, as well as the fact that if there was a means of micronized in sulphur without the need for grinding, contamination and the final product could theoretically be reduced insofar as the grinding media itself [albeit in minor quantities] would not contaminate the final product.